DEPARTMENT OF COMMERCE 


Circular 

of THE 

Bureau of Standards 

S. W. STRATTON. Director 


No. 41 


TESTING AND PROPERTIES OF 
TEXTILE MATERIALS 


[2ct Edition] 

Issued August 2 7, 1915 



WASHINGTON 

GOVERNMENT PRINTING OFFICE 








CIRCULARS ISSUED BY THE BUREAU OF STANDARDS 

1. Verification of Standards and Measuring Instruments. 

2. Measurements of Length and Area, Including Thermal Expansion. 

3. Verification of Standards of Mass. 

4. Verification of Standards of Capacity. 

5. Testing of Clinical Thermometers. 

6. Fees for Electric, Magnetic, and Photometric Testing. 

7. Pyrometer Testing and Heat Measurements. 

8. Testing of Thermometers. 

9. Testing of Glass Volumetric Apparatus. 

xo. Legal Weights (in pounds) per Bushel of Various Commodities. 

11. The Standardization of Bomb Calorimeters. 

12. Verification of Polariscopic Apparatus. 

13. Standard Specifications for the Purchase of Incandescent Lamps. 

14. Samples of Analyzed Irons and Steels—Methods of Analysis. 

15. A Proposed International Unit of Light. 

16. The Testing of Hydrometers. 

17. Magnetic Testing. 

18. Standard Gauge for Sheet and Plate Iron and Steel. 

19. Standard Density and Volumetric Tables. 

20. Electrical Measuring Instruments. 

21. Precision Measurements of Resistance and Electromotive Force. 

22. Standard Specifications for Transformers, Oil-immersed, Self-cooled, 60-cycle, 

2200 Volts. 

23. Standardization of Electrical Practice in Mines. 

24. Publications of the Bureau of Standards. 

25. Standard Analyzed Samples—General Information. 

26. Analyzed Iron and Manganese Ores—Methods of Analysis. 

27. The Testing and Properties of Optical Instruments. 

2S. The Determination of the Optical Properties of Materials. 

29. Announcement of a Change in the Value of the International Volt. 

30. Lime: Its Properties and Uses. 

31. Copper Wire Tables. 

32. Standards for Gas Service. 

33. United States Government Specifications for Portland Cement. 

34. The Relation of the Horsepower to the Kilowatt. 

33. Melting Points of Chemical Elements. 

36. The Testing and Properties of Electrical Condensers. 

37. Electric W r ire and Cable Terminology. 

38. The Testing of Rubber Goods. 

39. Specifications for and Measurement of Standard Sieves. 

40. Sodium Oxalate as a Standard in Volumetric Analysis. 

41. Testing and Properties of Textile Materials. 

42. Metallographic Testing. 

43. The Metric Carat. 

44. Polarimetry. 

45. The Testing of Materials. 

(Continued on third page of cover.) 



























. 














* 














DEPARTMENT OF COMMERCE 


Circular 

OP THE 

Bureau of Standards 

S. W. STRATTON, Director 


No. 41 


TESTING AND PROPERTIES OF 
TEXTILE MATERIALS 


[2d Edition] 

Issued August 2 7, 1915 



WASHINGTON 

GOVERNMENT PRINTING OFFICE 
1915 

n j 


Monograph 










ADDITIONAL COPIES 

OF THIS PUBLICATION MAT BE PROCURED FROM 
THE SUPERINTENDENT OF DOCUMENTS 
GOVERNMENT PRINTING OFFICE 
WASHINGTON, D. C. 

AT 

10 CENTS PER COPY 

2 


ft' sr o, 

SfP 8 J915 








TESTING AND PROPERTIES OF TEXTILE MATERIALS 


O'¬ 

'S 


CONTENTS 

Page 

I. Introduction. 4 

II. General information. 5 

III. Raw and unspun fibers. 6 

1. Identity of fiber or fibers. 6 

2. Approximate average length of fiber. 6 

3. Percentage of moisture and regain. 6 

4. Determination of oil or grease. 7 

5. Determining “ shrinkage ” of raw wool. 8 

IV. Determinations on yarn, thread, and twine. 8 

1. Length of yarn, thread, and twine. 8 

2. Tensile strength and elongation of yarn, thread, and twine. 9 

3. Yarn number or “count” of yarn, thread, and twine. 9 

4. Drying oven. 12 

5. Twist of yarn, thread, and twine. 12 

6. Determination of loading, sizing, and coloring material of yarn, 

thread, and twine. 13 

7. Percentage fiber composition. 14 

V. Fabrics. 14 

1. Weight. 14 

2. Tensile strength and elongation. 14 

3. Percentage fiber composition. 16 

4. Method of counting threads. 16 

5. Determination of the yarn number or size of yam in fabric. 17 

6. Folding endurance. 18 

7. Action of light on colors. 18 

VI. General instructions regarding applications for tests. 19 

1. Applications for test. 19 

2. Special tests. 19 

3. Identification marks. 19 

4. Shipping directions. 20 

5. Address.. 20 

6. Remittances. 20 

VII. Fees. 20 

1. Schedule 200.—Raw and unspun fibers. 20 

2. Schedule 201.—Yam, thread, and twine. 21 

3. Schedule 202.—Fabric. 21 

Appendix. 23 

1. Some results of textile tests. 23 

2. Adulteration of textile products. 24 

3. Influence of humidity upon the strength of yams. 25 


3 










































4 Circular of the Bureau of Standards 

I. INTRODUCTION 

The textile industry is one of the greatest of the manufacturing 
activities of the United States. Large quantities of raw wool, cot¬ 
ton, silk, jute, and many other kinds of fiber are continually 
being converted into various forms of finished product. These 
products are the basis of commercial transactions both in domestic 
and foreign markets, involving large sums of money and indirectly 
affecting every individual consumer. While supply and demand 
affect their money value, the quality and kind of the raw material 
and the process and care used in manufacturing determine to a 
considerable extent their economic value. It is therefore desirable, 
both for the raw materials and for the finished goods produced 
from them, to have methods of testing which may be easily applied 
and which will furnish a reliable means for reaching harmonious 
agreements between producer, distributor, and consumer. Ex¬ 
perience in the use of any material will show the characteristics 
which affect the suitability of that material for a certain purpose 
and the service which it may be expected to render. Having 
determined these characteristics, methods should be developed 
to measure them which will serve as a guide to both manufacturer 
and purchaser to assist them in determining in what degree they 
have been secured in individual cases. 

The accurate description of the material and quality required, 
supplemented by an indication of the conditions and methods of 
test by which they are to be determined, forms a specification 
regarding which it should be possible for the buyer and seller to 
reach an agreement. For some materials, like products of iron 
and steel, cement, and other structural materials, there have, in 
recent years, been developed through the cooperation of pro¬ 
ducers, consumers, and engineering societies standard specifica¬ 
tions and standard methods of testing. For textile materials no 
such standardization has been undertaken, and the industry is 
dependent very largely upon the units and methods of measure¬ 
ment as carried out by various manufacturers and individuals. 

The study of the physical and chemical properties of textile 
material by means of laboratory tests has been carried on in this 
country in a more or less desultory fashion for a great many years. 


Testing and Properties of Textile Materials 5 

The recent development of more systematic and greatly improved 
methods of testing has, however, given the results obtained much 
more significance than formerly. 

The present general interest in the establishment of standard¬ 
ized and better methods of testing has resulted in the introduction 
of testing apparatus in textile institutions, public testing labora¬ 
tories, stores, and mills. 

In England, France, Germany, Austria, Italy, and Japan ad¬ 
vanced methods of testing have been utilized with excellent results. 

Targe numbers of samples for investigation are being submitted 
to this Bureau not only by the Government departments but also 
by manufacturers, dealers, and other concerns and individuals. 
The fact that this work is rapidly increasing is good evidence of 
the value of the information received. 

The Bureau will gladly cooperate with institutions, investiga¬ 
tors, manufacturers, and consumers not only in the development 
of methods of testing and standardization, but also in furnishing 
information in its possession concerning methods of testing and 
the interpretation of results. It will be pleased to help in the 
design and construction of special testing apparatus. It is the 
object of this circular to outline the scope of work which is being 
undertaken by the Bureau and the range of fees for tests per¬ 
formed. It is not the policy of the Bureau, at present, to do com¬ 
mercial testing except for the Government departments, and for 
the public, in cases of dispute and where local facilities are not 
provided, in order that the Bureau’s efforts may be devoted to 
investigational work leading to the establishment of better 
specifications of textiles and methods of testing. 

II. GENERAL INFORMATION 

All weighings and physical determinations will be made upon 
instruments which have been carefully adjusted and calibrated, 
and will be performed in an atmosphere of 65 per cent relative 
humidity at 21 0 C (70° F) temperature, 1 if not otherwise specified. 

1 These conditions are adopted temporarily, as they represent approximately the average of the standards 
of various European testing houses. 



6 


Circular of the Bureau of Standards 


Such tests as weight, yarn number, and tensile strength will be 
made at bone-dry condition, i. e., subjecting the test specimens 
to 105° C. (221 0 F.) for two hours. 

Tests will be made upon all kinds of textile materials. In 
general, these materials may be classified as (a) raw and unspun 
fibers; ( b ) yarn, thread, twine, and rope; (c) fabric. 


III. RAW AND UNSPUN FIBERS 

Whether the sample is composed of one or more than one variety 
of fiber, tests will be made to determine (1) identity of fiber or 
fibers present; (2) approximate average length of fiber; (3) per¬ 
centage moisture and “regain” under any specified atmospheric 
condition within the Bureau’s range of temperature and humidity; 

(4) the percentage of oil, grease, or other foreign matter present; 

(5) “shrinkage” determination upon raw wool (by scouring and 
conditioning). 

1 . IDENTITY OF FIBER OR FIBERS 

This is ordinarily accomplished by careful inspection and by the 
use of the microscope and staining mediums, but other methods 
may be adopted from time to time after their accuracy and relia¬ 
bility has been definitely established. The Bureau has on hand a 
very complete collection of rare and commercial fibers and, if 
found necessary, recourse is had to these for comparison. To 
determine the percentage fiber composition of a mixture, the 
segregation and chemical methods outlined on page 16 are followed. 

2 . APPROXIMATE AVERAGE LENGTH OF FIBER 

The fibers under consideration are spread upon a velvet back¬ 
ground and carefully measured by a fine steel scale and magnifying 
glass. 

3 . PERCENTAGE OF MOISTURE AND REGAIN 

Moisture. —All textile fibers normally contain moisture, the 
amount varying according to the surrounding atmosphere. Since 
the physical properties of the material are affected by this moisture, 
it is extremely necessary for uniformity in testing that some con¬ 
ditions of humidity and temperature should be recognized as 
standard in this country. 


Testing and Properties of Textile Materials 


7 


The material being tested is conditioned—that is, exposed 
for a certain length of time to the standard atmosphere—(p. 5) 
and weighed. It is then dried in an oven and reweighed. The 
time and temperature required for proper drying depends upon 
the variety of material under consideration. From the difference 
between the air-dry and bone-dry weights, the percentage of 
moisture present is ascertained, employing the air-dry weight as a 
basis of calculation. 

Regain. —As there is some confusion regarding the meaning of 
the term “regain,” an explanation will be made. A sample of 
bone-dry textile material—that is, material which has been so 
dried that all moisture has been expelled except that of chemical 
composition—will, if placed in the above-mentioned standard 
atmosphere, absorb a certain quantity of moisture. This increase 
is known as the “regain weight.” From this is figured the “per¬ 
centage regain,” the bone-dry 7 weight being used as a basis of 
calculation. 

Under similar atmospheric conditions wool, cotton, silk, linen, 
jute, hemp, etc., will absorb percentages of moisture which vary 
somewhat with the sample, to a considerable extent with the 
grade and source of the fiber, and widely with the kind of fiber. 

4 . DETERMINATION OF OIL OR GREASE 

The method of procedure is to weigh the sample after exposure 
to standard atmospheric conditions, extract with ether, benzene, 
or other solvents, expose the fibers and the extract to the stand¬ 
ard atmosphere, and weigh both. 

The percentage of oil or grease is ascertained either from the 
weight of the extract or from the difference between the weights 
of the material before and after extraction. In some cases fibers 
will absorb more moisture with large quantities of oil present than 
with small amounts. This has been noted in some instances when 
experimenting with scoured wool. Therefore, perhaps, a more 
reliable procedure is to make all weighings on a bone-dry basis if 
there appears to be much oil in the sample. 

98060°—15 - 2 



8 


Circular of the Bureau of Standards 

5 . DETERMINING “SHRINKAGE” 2 OF RAW WOOL 

As applied to raw wool, the term “shrinkage” means the per¬ 
centage of dirt, wool grease, and foreign matter that may be 
washed out of the wool during the scouring process which neces¬ 
sarily precedes the carding of the fiber. 

In determining the shrinkage the following operations are 
performed: 

1. Weigh the sample after exposing it to standard atmospheric 
conditions. 

2. Scour at 48° to 55 0 C (120° to 130° F) temperature in water 
containing a sufficient quantity of neutral olive-oil soap. 

3. Wash thoroughly with cold water. 

4. Throw out the excess water in the scoured wool by the use 
of a centrifugal machine or “hydroextractor.” 

5. Dry in an oven at 105° C (221 0 F) to constant weight. 

6. Ascertain the quantity of grease remaining in the scoured 
wool and make the proper correction for it according to the 
methods outlined on page 7. From the dry weight, corrected 
for the remnant grease, the bone-dry shrinkage is obtained. If 
it is desired to know the air-dry shrinkage of the scoured wool, it 
is given a rough drying, then placed in the standard atmosphere, 
corrected for the grease content, and the shrinkage calculated 
from the weight thus obtained. 

IV. DETERMINATIONS ON YARN, THREAD, AND TWINE 

The important tests include the determination of (1) length; 
(2) tensile strength and elongation 3 or “elasticity”; (3) yarn 
number or “count”; (4) drying oven; (5) twist; (6) percentage of 
loading, sizing, or coloring material; (7) percentage fiber com¬ 
position. 

1 . LENGTH OF YARN, THREAD, AND TWINE 

Measuring.— The length test is made from the skein, cop, 
bobbin, spool, ball, or other form. 

In order to obtain the correct length of material for testing, 
recourse is had to the instrument known as the “ yarn reel.” The 

2 In the raw-wool trade “shrinkage” does not have reference to change of length, but simply to loss in 
weight by scouring. 

3 The term “elongation” may be considered as meaning either (a) The maximum stretch under breaking 
stress or ( b ) percentage stretch under any other given stress. 




Testing and Properties of Textile Materials 


9 


arms of this apparatus are carefully constructed and so connected 
that the amount of bending or other alteration is so small as to be 
negligible. 

The reeling is performed by passing the material through a 
smooth eyelet in a self-acting guide which lays the strands side 
by side so that the circumferential length is maintained unaltered 
throughout the winding. The reel is provided with an arrange¬ 
ment whereby certain tensions can be applied to the yarn being 
reeled and with a reliable counter and bell indicator to insure the 
correct number of turns being given. 

2 . TENSILE STRENGTH AND ELONGATION OF YARN, THREAD, AND 

TWINE 

Tensile strength and elongation can be determined from tests 
upon single strands or, if desired, upon skeins which have been 
wound upon either a 36-inch or a 54-inch reel. 

The instruments employed in these tests are of the dead-weight 
type. The pendulums are suspended upon knife edges, and stress 
is uniformly applied either by motor or by water pressure. These 
machines will register the strength and the elongation of the sam¬ 
ple, separately or simultaneously. They are carefully calibrated, 
and any necessary correction is made after the tests have been 
performed. The lower drum or clamp holding the yarn descends 
at a uniform rate of 12 inches per minute. 

All tests will be performed under standard atmospheric con¬ 
ditions and the yarn or twine being tested will be wound at least 
three times around a three-quarter-inch drum and securely held at 
either end, as shown in Fig. 1. The testing length between center 
of drums will be 6 inches and the pulling jaw will travel at a rate of 
12 inches per minute. Special tests can be made upon any length 
up to 20 inches and under any ordinary atmospheric condition. 

Unless otherwise requested, results will be reported as the 
average of 10 tests for the single-strand determination, or the 
average of 5 tests for the skein determination. 

3 . YARN NUMBER OR “COUNT” OF YARN, THREAD, AND TWINE 

The yarn number—that is, the relation between weight and 
length as expressed by the use of arbitrary commercial standards— 
is a fundamental basis for textile calculation. (See p. 17.) 


io Circular of the Bureau of Standards 

In testing for counts, four different results may be obtained by 
employing the following methods now in use: 

i. Determination of the weight of the sample as received. 



6 







f 



Fig. i .—Drums used in determining the tensile strength of twine 


2. Determination of the weight of the sample after it has been 
exposed to a specified standard atmosphere. 

3. Determination of the weight of the sample after all moisture 
has been driven out (i. e., the “bone-dry” weight). 

4. Determination of the “regain” weight. 







































































Testing and Properties of Textile Materials n 

In the first instance it will be readily understood that tests 
made for number upon yarn as received will give results which 
vary in accordance with the condition of the sample submitted. 
If the sample is in a very dry state, the resultant yarn number 
will be greater (the yarn will be lighter), or if submitted in a very 
damp state the resultant yarn number will be less (the yarn will 
be heavier) than if it were in accordance with normal conditions. 
The sample will not represent the bulk from which it was drawn 
unless it has been packed in an air-tight receptacle, as otherwise 
variation in weight will occur during transit according to the 
changing atmospheric conditions. 

The confusion now existing with reference to calculating the 
results might be minimized if a standard atmosphere as outlined 
in No. 2 should be agreed upon, as all lengths and weights would 
then be determined in this atmosphere. 

The basis of calculation in No. 3 is the “bone-dry” weight of 
the sample. In this instance the sample should first be exposed 
to the standard air conditions and the proper length taken. 

In the case of No. 4 the same procedure must be followed as for 
No. 3, and in addition the percentage “regain” must be added 
to the dry weight. This method is employed bv the Bureau of 
Standards, and the desired “regain” is added according to the 
specifications submitted. 

The “regain” of the various forms of textile material under 
atmospheric conditions, as mentioned on page 7, is now being 
determined. It is hoped that in the near future standard 
“ regains ” will be definitely adopted in this country as they are 
in Europe. 

The length of skeins and temperatures commonly used in com¬ 
mercial work for making yarn-number determinations are as 
follows: 


Fiber 

Length 

Temperature 


Yards 

120 

140° C (284° F) 


120 

105° C (221° F) 


20 or SO 

105° C (221° F) 


20 or 80 

105° C (221° F) 


50 

105° C (221° F) 
105° C (221° F) 


50 




















12 Circular of the Bureau of Standards 

If specially requested, these lengths will be used by the Bureau; 
otherwise such lengths will be used as seem to be best adapted to 
the individual case. 

4 . DRYING OVEN 

Bone-dry weighings are made in the oven shown in Fig. 2. 
The temperature of this oven is automatically maintained at the 
desired unit by a differential thermostat. A motor-driven fan cir¬ 
culates the atmosphere 
in the oven to insure uni¬ 
formity of heat distribu¬ 
tion. The sample to be 
weighed is placed in one 
of 10 small baskets car¬ 
ried by a chain. This 
chain may be turned by 
a wheel outside the 
oven, bringing each 
basket successively into 
such a position that it 
may be transferred to a 
hook suspended from 
one end of the balance 
beam by means of an¬ 
other hook operated 
from the outside of the 
oven. In this way 10 
samples may be dried 
simultaneously and weighed without any opening of the oven 
doors after the samples have been introduced. 

5 . TWIST OF YARN, THREAD, AND TWINE 

Yarn, thread, and twine necessarily contain more or less twist, 
the amount influencing the strength of the material and its adapt¬ 
ability for various uses. 

In all determinations of the number of turns per inch 20 tests 
will be made, and the average of these will be reported, unless 
otherwise requested. The length of the specimen examined will 
be 1 inch or more, according to the length of staple and such other 









Testing and Properties of Textile Materials 13 

considerations as the individual case may present. In the case 
of ply or folded material each test will be made on a 10-inch 
specimen, thus giving a result representing the average of 200 
inches of yarn. 

An instrument, specially designed for the purpose, is used in 
making these determinations. The specimen is held by two 
clamps. One of these is connected to a dial which may be turned 
to remove the twist from the specimen. The change in position 
of the dial shows the number of turns that have been given to the 
clamp, and therefore after all twist has been removed will show 
the number of turns originally present in the specimen. The 
other clamp is adjustable along a graduated bar, thus enabling 
the length of the specimen to be quickly and accurately regulated. 
A small spring attached to this clamp provides a uniform tension 
in the specimen, and an indicator carried by the spring shows the 
amount of elongation caused by the removal of the twist. The 
latter is only valuable in special cases and will not be reported 
unless requested. 

If requested, the Bureau will report the individual results of 
twist tests as well as the average. The regularity of the twist 
will often give additional information regarding the quality of 
the material. 

6 . DETERMINATION OF LOADING, SIZING, AND COLORING MATERIAL 

OF YARN, THREAD, AND TWINE 

The practice of adding to the weight of silk and to a less extent 
of cotton and other fibers during dyeing and finishing has become 
very common, and it is frequently necessary to ascertain the 
amount of true fiber present and the amount and kind of the 
weighting. 

Black-dyed silks have been weighted to the extent of more 
than 400 per cent and cotton to more than 50 per cent. Conse¬ 
quently, the knowledge of the extent and kind of this adulteration 
is very important in many cases. 

After weighing the sample to be tested in the standard atmos¬ 
phere the necessary treatment for the elimination of the adul¬ 
terant is performed. It is then weighed again under standard 
atmospheric conditions and the percentage of loss is computed 


14 Circular of the Bureau of Standards 

from the difference between these two weights. In some 
instances, depending upon the character of the loading, all weigh¬ 
ings are made with the sample in bone-dry instead of air-dry 
condition. 

7 . PERCENTAGE FIBER COMPOSITION 

Segregation Method. —The specimen under test is exposed 
to the standard atmosphere and weighed. Each yam is then 
carefully untwisted; the fibers of each different kind are placed 
in a separate pile in the standard atmosphere and weighed after 
proper exposure. The results of this test are checked or verified 
by the use of the microscope. 

Chemical Method. —The sample is weighed in the standard 
atmosphere and then the proper chemical procedure is followed, 
according to the constituent fibers present. 

V. FABRICS 

The following are some of the determinations made upon fabrics-: 
(i) Weight, (2) tensile strength and elongation, (3) percentage 
fiber composition, (4) thread count, (5) yam number or size, (6) 
folding endurance, (7) action of light on colors. 

1 . WEIGHT 

Unless otherwise specified, weighings will be made in the stand¬ 
ard atmosphere, and the results will be reported as ounces per 
square yard. They will also be reported, if desired, according to 
one of the following: 

1. Grams per square meter. 

2. Ounces per linear yard. 

3. Yards per pound. 

2 . TENSILE STRENGTH AND ELONGATION 

Test pieces are prepared by cutting samples 8 inches long by 1 
inches wide and then pulling out threads from both sides until the 
standard width of 1 inch is reached. 

The Bureau is prepared to make tensile-strength tests by either 
of two common methods: (a) Test specimens are exposed at least 
four hours to an atmosphere containing 65 per cent relative 
humidity at 21 0 C (70° F) temperature and then tested in this 
atmosphere; ( b ) test specimens are subjected to a temperature of 


Testing and Properties of Textile Materials 15 

105° C (221 0 F) for two hours, and then the breaking stress is 
determined while the moisture is completely eliminated. In the 
latter case the test specimens should be broken while hot and within 
* 


'-nuiiimiii , _ _ „ , , _ liiiiiiiiiuirr 

1 1 Jaws 0 / Ma chine 

1 u----- 



Fig. 3 .—Form of test specimen for cotton fabric 


30 seconds after being removed from oven. If requested, any 
other available condition will be used. 

Five samples each from warp and filling directions are taken from 
various parts of the sample. The usual length of the test speci- 




Fringt 


Jaws of Machine . 




N 


6 " 


k -- Q„ - N 

Fig. 4. —Form of test specimen for wool fabric 

men between the jaws or clamps of the testing machine is 3 inches 
for cotton fabric and 6 inches for wool, silk, linen, or jute fabric. 
The pulling jaw or clamp travels at a uniform rate of 12 inches per 
minute. The Bureau is equipped to make tests upon all fabrics 
breaking at less than 2200 pounds 
stress. The average results of 
tests are reported separately for 
warp and filling. 

Sampling Fabric for Strength 
Specimens. —For the determina¬ 
tion of the tensile strength, five 
test pieces each are cut from the 
warp and the filling. Fig. 5 illus¬ 



Fig. 5 .—Method of sampling fabric for 
tensile strength test specimens 


trates the method of sampling or cutting the test pieces. 






















































































16 Circular of the Bureau of Standards 

In order to enable the above tests to be made, the sample of 
fabric for test should be 18 inches long, if the cloth is 25 inches or 
more in width; but if less than 24 inches wide, then a 36-inch 
length should be furnished. 

3 . PERCENTAGE FIBER COMPOSITION 

If only one fiber is present, it is ascertained as outlined under 
“ Identity of fiber or fibers,” page 6. 

When composed of more than one kind of fiber, i. e., cotton, 
wool, silk, linen, etc., the following is an explanation of the usual 
methods of procedure: 

1. The weight of the fabric under standard air condition is found. 

2. A sample of convenient size is cut out and weighed as a whole. 
Then the warp and filling yams are weighed separately and the 
percentages of warp and filling are calculated from these results. 

Segregation Method. —Each warp yam is carefully untwisted, 
the different varieties of fiber (cotton, wool, silk, linen, jute, etc.) 
found are placed in separate piles in the standard atmosphere and 
weighed. If any difficulty is experienced in identifying the com¬ 
position of any pile, a chemical test combined with a microscopical 
examination is made. The same procedure is followed for the 
filling yams. 

ChEmicae Method. —For the ordinary determination a test 
specimen of about 4 square inches, or one ortwo repeatsof a pattern, 
is weighed in standard atmosphere, then treated with the proper 
chemical or chemicals. The latter is neutralized and washed with 
distilled water and then dried, weighed, etc., in accordance with 
the procedure considered correct. In this way one constituent is 
eliminated at a time and the percentages are obtained by simple 
calculation. 

For complicated fabrics a long series of tests is necessary, and 
this could only be outlined in a general way, because each fabric 
must be analyzed according to its fiber composition. 

4 . METHOD OF COUNTING THREADS 

An instrument called a “thread counter” is generally employed 
to ascertain the threads per centimeter or per inch. The ‘ ‘ counter ’ ’ 
carries a pointer which may be moved along a horizontal bar by 
means of a turnscrew. Directly above the pointer and moving 
with it is a low-power magnifying eyepiece through which each 


Testing and Properties of Textile Materials 


i7 


thread can be distinctly seen and readily counted. Under the 
pointer and resting upon the fabric under observation is a stationary 
piece of flat steel which is graduated to read to one-fourth inch divi¬ 
sions and to 0.5-cm divisions. It is therefore a comparatively sim¬ 
ple matter to count the threads of most fabrics. If the number can 
not be determined by this instrument, a higher power microscope 
is employed, or the threads in a measured distance are pulled out 
by hand and counted. This test is also often made with light 
transmitted through the fabric. 

The results of analysis, unless otherwise specified, will be reported 
as the number of threads per inch. If so desired, the number 
of warp ends across the full width of fabric will be determined. 

5 . DETERMINATION OF THE YARN NUMBER OR SIZE OF YARN IN FABRIC 

The terms “yarn number” and “size” are commonly used to 
indicate the length of yarn per unit weight. 

There are many systems of yarn numbering now in use. These 
are, for the most part, based upon arbitrary quantities, which 
differ according to the kind of material, the locality, or often the 
preference of the individual. Samples submitted to the Bureau 
for this determination should therefore be accompanied by a state¬ 
ment of the particular system it is desired to use. Otherwise the 
report will be made in terms of the system which is thought will be 
desired and most valuable. 

The knowledge of the size of the yarn is necessary to spinners, 
cloth manufacturers, and to large consumers of yarn and fabric. 
It is obvious that spinners and cloth manufacturers must know the 
size of the yarn they are to manufacture, and the large consumer 
should give this information to the spinner in the form of a 
specification. 

To illustrate the method of procedure in the case of a cotton 
fabric, the following example is given: 

If the yarn number is desired in the warp direction only, 60 
yams each 24 inches long (equals 40 yards) from three different 
parts of the cloth are taken, aggregating 120 yards. If both the 
warp and filling are tested, shorter lengths are employed. Three 
tests are made for warp threads and six tests for filling threads, 
the latter generally being more irregular than the former. 

The method of determining the yam number in this case is the 
same as given in the procedure for yam, thread, and twine (p. 9). 


i8 


Circular of the Bureau of Standards 


6 . FOLDING ENDURANCE 

Materials such as silk, book cloths, and window-shade cloth, when 
in actual use are subjected to folding to a considerable extent. In 
such eases folding endurance tests will show to what extent they 
may be expected to resist deterioration from this cause. In silk 
and book cloths that have been heavily weighted this test is an 
especially important one, as the material is then liable to be seri¬ 
ously damaged after short usage by cracking or splitting. 

The folding test is made upon a specially constructed machine 
which registers the number of alternate folds the specimen endures 
before breaking under a given constant tension. The determi¬ 
nation is made in the standard atmosphere upon a test strip 

15 mm (19/32 inch) wide and 95 
mm (3H inches) long. The num¬ 
ber of double folds 4 made before 
rupture occurs is reported. A 
constant tension of 1000 g (35 
ounces avoirdupois) is applied 
during the folding operation and 
the double folds are made at a 
rate of 200 per minute. 

The machine used is called the 
“Schopper” folding machine and 
is the only instrument now 
available for such determina¬ 
tions. Other concerns, however, are constructing machines for this 
purpose and some of them will probably be completed during this 
year. 

7 . ACTION OF LIGHT ON COLORS 

The permanency of the coloring material of certain fabrics when 
exposed to the action of sunlight is a matter of considerable 
importance. 

Test strips of cloth are fastened to a board, one-half of each 
strip being covered and the other half exposed to direct sunlight. 
After various intervals the sample is examined to observe what 
change has occurred in the exposed portion. 

4 By a double fold is meant that the sample is folded flat upon itself, then opened and folded at the same 
point flat upon itself in the reverse direction. 



Fig. 6 .—Folding machine 








Testing and Properties of Textile Materials 


19 


Degree of Light Effect. —The result of tests of light action 
after any specified exposure will be reported as follows: (1) None; 
(2) slight (lighter or darker); (3) medium (lighter or darker); 
(4) decided (lighter or darker). 

VI. GENERAL INSTRUCTIONS REGARDING APPLICATIONS 

FOR TESTS 

1 . APPLICATIONS FOR TEST 

All articles submitted for test should be accompanied by a writ¬ 
ten request. This request should enumerate the material or mate¬ 
rials, giving an identification mark, and should state explicitly the 
nature of the testing desired. When the test is one regularly pro¬ 
vided for in the appended schedule, the fee may be computed in 
advance and should be sent with the request for the test at the 
time the material is shipped. When an article or material is sent 
simply for test without definite instructions the Bureau will, when 
practicable, decide upon the nature of the test without corre¬ 
spondence. 

2 . SPECIAL TESTS 

The Bureau will gladly cooperate with scientific investigators, 
manufacturers of apparatus, and others who need higher precision 
than is provided in the regular tests, as far as the regular work of 
the Bureau will permit. Kinds of tests not at present provided 
for may be undertaken if the work is important and the facilities 
and time are available. Approved tests not provided for in the 
regular schedules will be considered special, and a special fee will 
be charged for them. The test should be arranged for by corre¬ 
spondence before shipment of the material. The application 
should state fully the need for the test, and the precision required. 
The special fee charged will depend chiefly upon the time con¬ 
sumed and the amount of alteration required in the regular testing 
apparatus. An estimate of the fee will be given when possible. 

3 . IDENTIFICATION MARKS 

All packages should be plainly marked with the shipper’s name 
and address and a list of the contents. Each separate piece or 
sample of material should be provided with an identification mark 
or number. The identification mark should also be given in the 
application for the test. 




20 


Circular of the Bureau of Standards 


4 . SHIPPING DIRECTIONS 

Apparatus or test specimens should be securely packed in cases 
or packages which will not be broken in transportation and which 
may be used in returning them to the owner. The shipment in 
both directions is at the applicant’s expense and risk. The tops 
of boxes should be put on with screws, as the jar due to nailing and 
the subsequent opening is liable to cause damage. The tops of 
the shipping boxes should have the return or forwarding address 
on the underside. Transportation charges are payable by the 
party requesting the test. The charges for shipment to the Bureau 
must be prepaid, and, unless otherwise arranged, articles will be 
returned “charges collect.” 

5 . ADDRESS 

Material submitted for test, as well as all correspondence, should 
be addressed simply “Bureau of Standards, Washington, D. C.” 

6 . REMITTANCES 

Fees in accordance with the appended schedules should be sent 
when the material or apparatus is shipped, or promptly upon 
receipt of bill. Certificates are not given, nor is material returned, 
until the fees due thereon have been received. Remittances may 
be made by money order or by check drawn to the order of the 
“Bureau of Standards.” 

VII. FEES 

The following schedule of fees for testing textile material will 
be followed in general from the date of issuance of this revised 
circular. The Bureau reserves the right, however, to make extra 
charges for any tests presenting unusual difficulties or to make 
changes in the schedule without notice. 


1 . Schedule 200 .—RAW AND UNSPUN FIBERS 

(a) Identification of fiber (if composed of one fiber only). $i. oo 

( b) Identification of a mixture of fibers. 2. oo 

(c) Quantitative determination of a mixture. 3- oo 

(d) Determination of the approximate length (if composed of one fiber 

only).. i. oo 

(e) Determination of the approximate length (if composed of two or more 

fibers).. 2. 00-3. 00 







Testing and Properties of Textile Materials 21 

(/) Quantitative determination of moisture. $1. 50 

( g ) Determination of the percentage of oil or grease. 3- 00 

(h) “Shrinkage” determination of raw wool (scouring and conditioning).. 2. 50-5. 00 

2 . Schedule 20 L—YARN, THREAD, AND TWINE 

(a) Measuring of skeins, cops, bobbins, spools, or balls (average of two 

tests), one sample: 

(1) Lengths up to 1000 yards. 1. 00 

(2) Lengths over 1000 yards. 1.50 

(b) Tensile strength determination (average of 10 tests), one sample: 

(1) Breaking stresses from o to 1 kg (2.2 pounds). .50 

(2) Breaking stresses from 1 kg (2.2 pounds) to 50 kg (no pounds). 1. 00 

(3) Breaking stresses from 50 kg (no pounds) to 1000 kg (2200 

pounds). i- 50 

(c) Elongation determination (average of 10 tests), one sample: 

(1) Determined at breaking stress of specimen. 1. 50 

(2) Determined under a specified stress. 1. 50 

( d) Twist determination (average of 20 tests), one sample: 

(1) Single or one-ply strand. 1. 50 

(2) Folded or ply yarn. 1. 00 

(e) Determination of yam number (average of five tests), one sample. 2. 00 

(/) Identification of fiber (if composed of one fiber only). 1. 00 

( g ) Identification of a mixture of fibers. 2. 00 

( h ) Percentage fiber composition, one sample: 

(1) If composed of two fibers only... 3. 00 

(2) If composed of more than two fibers. 3-5° 

(t) Diameter of cord or rope. .25 

3 . Schedule 202 .—FABRIC 

(a) Weight, one sample. .50 

( b ) Tensile strength determination (average of five tests upon warp and 

filling, respectivelv), one sample. 1. 50 

(c) Elongation determination (average of five tests upon warp and filling, 

respectively), one sample: 

(1) Determined at breaking stress of specimen. 2. 00 

(2) Determined under a specified stress. 2. 00 

(d) Fiber composition (percentage composition of warp, filling, and of 

whole fabric), one sample: 

(1) If composed of two fibers only. 3. 00 

(2) If composed of more than two fibers. 3. 50 

(3) Quantitative determination of warp or filling yams, one 

sample (same as for Schedule 201 h). 

(e) Threads per inch (average of 10 tests both in warp and filling direc¬ 

tions), one sample. .50 

(/) Determination of yam number, one sample: 

(1) Yarn number of warp. 2. 00 

(2) Yam number of filling.. 2. 00 

(3) Average yam number of whole fabric. 2. 00 




























22 Circular of the Bureau of Standards 

( g) Folding determination, one sample: 

(1) Testing less than 1000 double folds. $i. oo 

(2) Testing between 1000 and 10 000 double folds. 1. 50 

(3) Testing between 10 000 and 100 000 double folds. 2. 00 

(4) Testing more than 100 000 double folds. 2. 50 

(h) Quantitative determination of starch, one sample. 1. 50 

(i) Quantitative determination of moisture, one sample. 1. 50 

(j) Action of light on colors, one sample. 1. 00 

( k ) Action of w r eather on colors, comparison of two samples. 1. 00 

(/) Action of weather upon the tensile strength, one sample. 3. 00 

( m ) Fastness to washing, one sample. 1. 00 

( n) Determination of thickness, one sample. .50 

S. W. Stratton, 

Director. 

Approved: 

E. E. Pratt, 

Acting Secretary. 













\ 


APPENDIX 

1 . SOME RESULTS OF TEXTILE TESTS 

The tensile strength depends upon the quality and kind of 
material employed and the method of manufacture. The particu¬ 
lar application that is to be made of the finished product determines 
the weight, threads or yarns per inch, yardage, composition, etc., 
used in manufacturing. Results of tests upon some of the more 
common textile materials are given in the following tables: 


TABLE l 

Results of Tests on Fabric Used in the Manufacture of Cotton Bags 


Used as container for— 

Weight 

per 

square 

yard 

Tensile strength 

Threads per inch 

Warp 

Filling 

Warp 

Filling 


Ounces 

Pounds 

Pounds 



5 pounds of sugar. 

2. 75 

25 

15 

64 

60 

10 pounds of sugar. 

3.5 

35 

20 

76 

66 

5 pounds of salt. 

3. 25 

25 

15 

48 

44 

One-half bushel of seeds. 

5. 75 

70 

25 

70 

40 

100 pounds of cement. 

8.0 

125 

44 

85 

32 

Do.. 

8.5 

75 

85 

40 

30 


TABLE 2 

Results of Tests of Common Tying Twines 


Cotton 


Jute 


Tensile strength 
in pounds 

Yards 

per 

pound 

Tensile strength 
in pounds 

Yards 

per 

pound 

10 

1675 

20 

650 

15 

1050 

25 

625 

20 

850 

50 

350 

25 

675 

75 

125 

50 

300 

150 

70 

75 

150 

225 

40 


23 








































24 


Circular of the Bureau of Standards 


TABLE 3 

Results of Tests Upon Various Fabrics 


Use or name of fabric 

Weight 

per 

square 

yard 

Tensile strength 

Threads per inch 

Warp 

Filling 

Warp 

Filling 


Ounces 

2.0 

Pounds 

16 

Pounds 

10 

38 

34 


2. 25 

25 

30 

76 

64 


2. 25 

30 

45 

90 

84 

Linen bed sheets. 

3.0 

60 

35 

86 

84 

Chambray. 

4.0 

40 

35 

76 

64 

Cotton bed sheets. 

4. 5 

65 

50 

72 

60 

Gingham. 

4. 75 

65 

30 

82 

38 

Bed ticking. 

7.75 

105 

60 

76 

58 


8. 0 

110 

60 

70 

40 

Huck towel, linen and cotton. 

8.5 

95 

75 

54 

30 

Roller toweling. 

9.0 

100 

85 

64 

30 

Awning cloth. 

10.0 

180 

72 

48 

34 

Burlap (jute). 

10.5 

55 

75 

12 

12 

Light-weight cotton canvas. 

10. 5 

130 

100 

54 

36 

Tire fabric (Egyptian). 

17. 25 

280 

290 

23 

23 

Tire fabric (Sea Island). 

17. 25 

300 

320 

23 

23 

Heavy cotton canvas. 

27.75 

200 

315 

30 

22 





2 . ADULTERATION OF TEXTILE PRODUCTS 

The results of tests shown in the table below give some of the 
adulterations and the misrepresentation of some goods which are 
found in material commonly sold to the consumer: 

TABLE 4 


Name of material 

Advertised composition 

Found upon analysis to contain— 

Wool yarn waste. 

100% wool. 

15% wool and 85% jute 

10% wool and 90% cotton 

35% wool and 65% cotton 

50% wool and 50% cotton 

75% wool and 25% cotton 

75% wool and 25% jute 

100% cotton 

Do. 

Wool blanket.... i. 

.do. 

Do. 

.do. 

Wool dress goods. 

.do. 

Wool yam. 

.do. 

Wool blanket. 

.do. 

Linen thread. 

100% linen. 

Linen tape. 

... .do. 

Linen fabric. 

.. .do. 

Do. 

Linen towel. 

.do. 

50% linen and 50% cotton 

100% jute 

Do. 

Flax twine. 

100% flax. 

Flax packing. 

.do. 

Flax twine. 

.do. 

50% flax and 50% jute 

100% Kentucky hemp 

30% silk and 70% mercerized cotton 
50% silk and 50% artificial silk 

75% silk and 25% artificial silk 

Italian hemp twine. 

100% Italian hemp. 

Silk tape. 

100% silk. 

Silk hosiery. 

.do. 

Silk fabric. 

.do. 















































































Testing and Properties of Textile Materials 


25 


3 . INFLUENCE OF HUMIDITY UPON THE STRENGTH OF YARNS 

The necessity for exposing all test pieces to the same atmos¬ 
pheric conditions is well illustrated by a series of tensile-strength 
tests that have been made upon cotton and worsted yams. Suc¬ 
cessive determinations were made on the same yarns, after they 
had been exposed to various degrees of humidity, the temperature 
remaining constant at 70° F. The results obtained were plotted 
in the accompanying diagrams. It will be observed that, in the 
case of the cotton yarns, the strength shows a regular increase 
according to the humidity, while the strength of the worsted yarns 
decreases. The degrees of humidity were not at all extreme and 
any of the results might have been obtained from yarns tested 
under prevailing conditions. 

Fig. 7 shows an increase of 16 per cent in tensile strength and 
Fig. 8 shows a decrease of 18 per cent in tensile strength for 40 
per cent increase of humidity. 


660 

65 0 

640 

6 JO 

*■> 6 20 
*■» 

£ 

9 

W 

O 

V-r 

6 1 0 
•C 

c 

600 

<0 

QJ 

<0 

5 

K 

5 80 

57 0 












'64-8 






xf 

' 62 8 



4? 

9 








599 







' 575 





45 55 65 75 85 


Percent Relative Humidity 

Fig. 7 .—The tensile strength of cotton yarns under different atmospheric conditions 

















26 


Circular of the Bureau of Standards 



45 55 65 ?5 85 

Percent Relative Humidity 

Fig. 8 .—The tensile strength of worsted yarns under different atmospheric conditions 


& 





































































































































































(Continued from second page of cover.) 

46. Testing of Barometers. 

47. Units of Weight and Measure; Definitions and Tables of Equivalents. 

48. Standard Methods of Gas Testing. 

49. Safety Rules to be Observed in the Operation of Electrical Equipment and Lines. 

50. National Standard Hose Couplings and Fittings for Public Fire Service. 

51. Measurement of Time and Tests of Timepieces. 

52. Regulation of Electrotyping Solutions. 

53. Composition, Properties, and Testing of Printing Inks. 

54. Proposed National Electrical Safety Code. 

55. Measurements for the Household. 

[A complete list of Scientific Papers, Circulars, and miscellaneous publications 
may be obtained free of charge on application to the Bureau of Standards, Washing¬ 
ton, D. C.] 


























